Gear actuated predetermined torque release wrench



May 26, 1953 J. w. STIRZELA 2,539,637

GEAR ACTUATED PREDETERMINED TORQUE RELEASE WRENCH Filed March 5, 1952 2 Sheets-Sheet 1 IN VEN TOR.

BY W R M fiigrzw y y 26, 1953 J. w. STIRZEL 2,639,637

GEAR ACTUATED PREDETERMINED TORQUE RELEASE WRENCH Fi led March 5, 1952 2 Sheets-Sheet 2 I| lu j ry" 5.

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207 15 2 121 g. 126' 06 0 27- 1 j 204 I 6%? 1 1.9 l i, I M

*14 INVEN.TOR.

Patented May 26, 1953 UNITED STATES i ATENT OFFICE GEAR ACTUATED PREDE'EERMINED TORQUE RELEASE WRENCH 14 Claims.

My invention relates to torque wrenches, more particularly to compact and simplified apparatus for applying relatively large torque forces to threaded connections, and has for an object to provide improved apparatus of this character.

Torque wrenches in general use at the present time involve lever-like handles of lengths up to several feet, by means of which one or more operators apply manual force. As such manual force applied through a long handle is increased, the application becomes more difficult to control, with the result that the performance is exceeding erratic and unsatisfactory.

Furthermore, while torque wrenches frequently incorporate indicating devices so that the operator may know at all times the torque being applied, such indicators usually are mounted adjacent the work-engaging end of the handle, and hence are not readily readable by the operator working at the other end of the handle, several feet away from the indicator.

This last-mentioned problem has been recognized by the industry, but the only solutions thereof of which I am aware involve the use of a signal lamp which is illuminated when a predetermined desired torque is attained or a secondary lever so set as to give a click when the desired stress is attained; Even these solutions of the problem are subject to the serious objection that the desired torque is frequently exseeded, due to the unsteady or jerky application of force to the lever.

Accordingly, another object of my invention is the provision of apparatus by which large torque forces may be applied smoothly and with uniformly-increasing pressure.

Another object of my invention is the provision of a torque wrench incorporating torqueindicating means so disposed as to be readily observable by the operator during use of the apparatus.

Yet another object of my invention is the provision of a torque whench incorporating a coacting worm and gear sector through which a moderate input force is multiplied to a large torque output.

These and other objects are effected by my invention as will be apparent from the following description and claims, taken in accordance with the accompanying drawings forming a part of i this application, in which:

Fig. 1 is a perspective view of a torque wrench constructed in accordance with the present invention;

Fig. 2 is an enlarged detail sectional view, taken 2 along the line II-II of Fig. 1, looking in the direction indicated by the arrows;

3 is a sectional side elevational View of the structure shown in Fig. 1;

Fig. 4 is an enlarged transverse sectional view of a nut to be tightened, together with a special washer utilized therewith in accordance with my invention;

5 is a, top plan view of a modified form of torque wrench incorporating my invention;

5 is a side elevational view of the apparatus shown in Fig. 5 with a portion thereof shown in section taken along the line VI-VI of Fig. 5, looking in the direction indicated by the arrows; and.

Fig. 7 is an enlarged side elevational view of a modified nut and associated special washer.

Referring now to the drawings in greater detail, and particularly to Figs. 1 to 4, inclusive, the reference character iii indicates, in its entirety, a torque multiplier or torque wrench illustrated in operable association with a nut II to be tightened on a bolt 52 extending through aligned openings 53 in abutting sheets of material M.

Preferably the torque wrench it includes 2. cylindrical torsion rod it having formed thereon at one end a projection ll of non-circular cross section for reception in a mating recess 28 in a conventional socket it, mating with the nut H.

Mounted on the torsion rod it intermediate its length is an arm or lever 2 l, the torsion rod and the lever it being maintained in non-rotatable relation to each other by suitable means, such as the transverse pin 22. As best shown in Fig. l, the lever 2| terminates at its free end in a worm sector 23 meshing with, and driven by, a worm mounted on the power input shaft 25. This shaft 26 is journaled in a frame element 2'! and may be rotated by any suitable means, for example, the crank 28. Obviously, the shaft 26 may be turned by power means rather than manually, if desired.

The frame element 21, in which the worm shaft 26 is journaled, is supported by a pair of spaced arms 3! and El. The arm 3! is provided at one end with an opening 32 for reception of a mating terminal portion 33 at that end of the torsion rod H5 opposite its socket-engaging portion ii. The other end of the arm 3| is provided with a T-head 34 resting on the frame 2? and having a spaced pair of openings 35 for reception of pins 38 on the frame.

The other arm 31 includes a cylindrical terminal portion 38 having an axial bore 39 receiving a stud 4| depending from the frame 21. The stud 4| is of sufficiently greater length than the cylindrical terminal portion 38 of the arm 31 to provide for vertical adjustment of the frame element 21 relative to the lower arm 31, as may be required when sockets I9 of various heights are used. The desired vertical adjustment is maintained by use of a spacer 43 of the necessary thickness around the stud 4| between the frame 21 and the cylindrical portion 38.

The arm 31 is bifurcated at its other end to provide upper and lower fingers 46 and 41, respectively, spaced axially of the torsion rod a distance exceeding the height of the socket I9, the socket being straddled by the bifurcation. The upper finger 46 terminates in a semicircular portion 48, adapted to embrace the torsion rod I6 near its lower end. The lower finger 41 is further bifurcated by the slot 49 having parallel sides (see Fig. 2).

Attention is now directed to Fig. 4, wherein there is illustrated a special washer 52 comprising a square, or otherwise non-circular, base 53 and an overlying flange 54 which may be circular or otherwise. In the construction of washer shown in Fig. 4, the base 53 has a central up wardly-directed flange or collar 56 projecting through the central opening 51 of the flange 54 and deformed radially outward over the latter,

as at 58, to retain the flange 54 and the base 53 in assembled relation. The relatively narrow deformed portion 58 at the upper surface of the washer 52, compared with the much greater bottom surface of the base 53, assures that when the nut II is turned down on the bolt I2 and grips the washer against the material I4, there will be relative rotation only between the nut and the washer, and not between the washer and the material I4. In other words, as the nut is tightened, the washer is prevented from being rotated through contact with the turning nut, as the total area of engagement between the nut and the washer is materially less than the total area of engagement between the washer and the material on which it rests. As an alterlower arm 31, and hence of the frame element 21, during operation of the torque wrench.

In operation, it is assumed that the nut II has first been partially tightened on the bolt I2 by any conventional wrench, which will result in the special washer 52 being gripped suificiently tight to prevent its rotation. The torsion rod IS, with its socket I9, is placed over the nut, and the lower arm 31 of the torque wrench I0,

with the frame element 21 mounted thereon,

is placed against the torsion rod with the slotted 'lower finger 41 embracing the base 53 of the 'washer. worm 24 will mesh with the teeth of the gear sector 23. Thereafter the upper arm 3| is connected to the top of the torsion rod and to the When so positioned, the thread of the top of the frame element 21, and the apparatus is ready for use.

It will be apparent to those skilled in the art that rotation of the crank 28 in the proper direction will operate through the worm and gear sector to rotate the lever 2I, and hence the torsion rod I6 to which it is secured, thereby tightening the nut II on the bolt I2.

The torque wrench I0 may be provided with a suitable torque-indicating gauge 60, including the usual first and second relatively movable elements GI and 62, respectively. As herein shown, the first element 6| is mounted on the lever 2 I, while the second element 62 is mounted on the torsion rod I6, at a point thereon spaced axially a material distance from the lever 2|. Application of torsional forces to the torsion rod will result in relative motion of the elements GI and 62 of the gauge 60, thereby effecting movement of the indicator 63 of the gauge.

Referring now to sheet two of the drawings, and particularly to Figs. 5 and 6 thereon, the structure shown is generally similar to that already described. The primary difference is that the lever |2| is free to rotate on the torsion rod I I8, and torquing forces are transmitted from the worm I24 to the gear sector I23 and from the sector through depending lugs 20!] thereon to the free end of a spring arm or lever 2III which is secured to the torsion rod H6 and transmits torsional forces thereto.

The frame element I21, worm I24, shaft I26, crank I28, upper and lower arms I3I and I31, respectively, all are similar to the corresponding parts of the earlier-described form of the invention.

In this modification of the invention the gauge comprises a first element 204 in the form of an indicator, secured to the torsion rod IIB by a pin 206, and a second element 201 in the form of a scale or indicia provided on the upper surface of the gear sector I 23. As the torsion rod is twisted, movement of the scale 201 relative to the indicator 204 will occur, thereby providing a reading on the scale.

In Fig. '7 there is shown a modified form of nut 2 I I and cooperating washer 252, wherein the reduced area contact surface between the nut and Washer is provided by a depending flange 2 I2 on the lower surface of the nut 2| I, and the washer is lacking any upwardly-extending flange or projection above the surface of the radial flange I54.

While the invention has been shown in several forms, it will be apparent to those skilled in the art that it is not so limited, but is susceptible of changes and modifications without departing from the spirit thereof.

What is claimed is:

1. Apparatus of the character described comprising a work-engaging member, an arm secured to said work-engaging member, supporting structure associated with said work-engaging member, manually-operable force-applying means carried by said supporting structure, means for transmitting force from said force-applying means to said arm, means for retaining said supporting structure stationary during operation of the forceapplying means carried thereby, and a torsion gauge comprising first and second elements, said first element being secured to said arm and said second element being secured to the work-engaging member at a point thereon spaced longitudinally thereof relative to the point of securement thereto of the arm, and means cooperating with said first and second elements, and operating in response to torsion in the work-engaging between said two points of securement for indicating attainment of a predetermined amount of torsion,

2. Apparatus for tightening a threaded conspaces? mention -between a; pair of threaded articles, comp an elongated article-engaging -member, a 'leversecuredat one end to said elongated-articleengaging member intermediate the lengtho-f the latter, a supporting bracket detachably assoc-i ated with the article-engaging member and including firstzand seconds-paced arms each having one end detachably associated with the article- .engaging member at opposite sides or the lever and. a frameelem-ent joining the other ends of said first and second spaced arms, force-applying means carried by said frame element, means :for transmitting force from said force-applying means to the lever at the other end of the latter,

and means for retaining said supporting bracket stationary during operation of the force-applying means.

3. Apparatus for tightening a threaded connection'between a, pair of threaded articles, 'CQL-" prising an elongated article-engaging member, .a "lever secured at oneend to said elongated articleengaging member intermediate the 'len-gthlof the latter, a supporting bracket detachably associated with the article-engaging member andrincluding first and second spaced arms each having one end detachably associated with the articleengaging member at opposite sides of the lever and a frame element joining the other ends of said first and second spaced arms, a shaft journaled in said frame element, means for applying torque to said shaft, a worm secured on said shaft, a worm sector meshing with said worm and operatively associated with the other end of the lever, whereby torque applied to said shaft is transmitted to said lever and therethrough to the article-engaging member, and means retaining said supporting bracket stationary during operation of said torque-applying means.

4. Structure as specified. in claim 3, including a torsion gauge including first and second elements, said first element being secured to said lever and said second element being secured to said article-engaging member at a point thereon spaced longitudinally thereof relative to the point of securement thereto of the lever, and means cooperating with said first and second elements and. operating in response to torsion in the article-engaging member between said two points of securement for indicating attainment of a predetermined degree of torsion.

5. Apparatus of the character described, comprising a torsion rod having one end thereof formed to non-rotatably engage a socket; a lever mounted at one end on said torsion rod in nonrotatable relation thereto; a supporting bracket associated with said torsion rod and including a frame element spaced from and approximately parallel to the torsion rod, a first arm extending from one end of said frame element to the corresponding end of the torsion rod in bridging rela tion to the space therebetween, and a second arm extending from the other end of the frame element to a point in axial alignment with, but beyond the other end of the torsion rod; forceapplying means carried by said frame element; means for transmitting force from said force applying means to the free end of the lever; means for retaining said supporting bracket sta tionary during operation of the force-applying means.

6. Apparatus for applying torque to one member of a pair of threadedly-connected members having a non-circular washer therebetween; said apparatus comprising a torsion rod, a lever se- 6 cured at one end to said torsion rod in nonrotatable relation thereto, a supporting bracket associated with said torsion rod and including a frame clement spaced from and approximately parallel to the torsion rod, a first arm detachably connected at one end to one end of the frame element and at the other end to the corresponding end of the torsion rod and bridging the space between said frame element and said torsion rod, and a second arm secured at one end to the other end of the frame element and having its other end formed with an open-ended parallelsided slot adapted to ncnrotatably receive the non-circular washer; force-applying means mounted in said frame element; and means for transmitting force from said force-applying means to the free end of the lever to swing the lever about the longitudinal axis of the torsion rod, thereby applying torque to the latter.

'7. Structure as specified in claim 6, including a torsion gauge comprising first and second elements, said first element being secured to the lever and said second element being secured to the torsion rod at a point thereon spaced longitudinally thereof relative to the point of securement thereto of said lever, and'means cooperating with said first and second elements and operable in response to torsion in said torsion rod between said two points of securement for indicating attainment of a predetermined degree of torsion.

8. Apparatus for applying torque to one member of a pair of threadedly-connected members having a non-circular washer therebetween: said apparatus comprising a torsion rod; a lever secured at one end to said torsion rod in nonrotatable relation thereto; a supporting bracket associated with said torsion rod and including a frame element spaced from and approximately parallel .to the torsion rod, a first arm connected at one end to an end of the frame element and at its other end to the corresponding end of the torsion rod, a second arm secured at one end to the opposite end of the frame element and having its other end formed with an open-ended parallel-sided slot adapted to non-rotatably encage the non-circular washer; a shaft journaled in said frame element; means for applying torque to said shaft; a Worm secured on said shaft; and a worm sector meshin with said worm and operatively associated with the free end of the 1ever, whereby torque applied to said shaft is transmitted to said lever and therethrough to the torsion rod.

9. Apparatus for applying torque to one member of a pair of threadedly-connected members, comprising a non-circular washer positioned between said members, a torsion rod, a lever secured at one end to said torsion rod in nonrotatable relation thereto, and including a supporting bracket associated with said torsion rod, a frame element spaced from and approximate- 1y parallel to the torsion rod, a first arm detachably connected at one end to one end of the frame element and at the other end to the corresponding end of the torsion rod, and a second arm secured at one end to the other end of the frame element and having its other end formed with an open-ended parallel-sided slot ada ted to non-rotatably receive the non-circular washer, force-applying means supported by said frame element, and means for transmitting force from said force-applying means to the free end of the lever to swing the latter about 7 the longitudinal axis of the'torsion rod, thereby applying torque to the latter.

10. In apparatus for applying torque to one member of a pair of threadedly-connected members, a washer adapted to be positioned adjacent one of said members and clamped thereagainst upon application or torque to said firstmentioned one member, said washer comprising a base portion of non-circular outline, and a radial flange extending therebeyond.

11. In apparatus for applying torque to one member of a pair of threadedly-connected members, a Washer adapted to surround one of said members and be clamped by the other of said members, said washer comprising a flat annular flange portion and a base portion of lesser diameter than said flange portion and having a pair of parallel spaced sides.

12. In apparatus for applying torque to one member of a pair of threadedly-connected members, a washer adapted to surround one of said members and be clamped by the other of said members, said Washer comprising a flat radiallyextending fiange portion, a base portion below the flange portion and having a pair of parallel spaced sides, and an axially-extendin flange portion having a member-engaging surface of lesser area than the bottom of said base portion.

13. Apparatus for applying torque to one member of a pair of threadedly-connected members, comprising a locking element adapted to be positioned beneath said one member and clamped by the latter against rotation relative to the other member of said pair of threadedly-connected members, a torsion member adapted to non-rotatably engage said one member, supporting structure associated with said torsion member, force-applying means carried by said supporting structure, means for transmitting force from said force-applying means to said torsion member, and means for temporarily connecting 8 said supporting structure to the locking element to prevent rotation of said supporting structure relative to said other member of said pair 01' threadedly-connected members during application of torque to said one member by said apparatus.

14. Apparatus for applying torque to a nut threadedly-mounted on a stud or bolt extending normal to a fiat surface of a body, comprising a torsion member adapted to rotate the nut on the stud or bolt, supporting structure associated with said torsion member, force-applying means carried by said supporting structure, means for transmitting force from said force-applying means to said torsion member, a locking element adapted to be non-rotatably clamped between the nut and the flat surface of the said body, and means for temporarily connecting said supporting structure to said locking element to prevent rotation of the supporting structure relative to the stud or bolt during application of torque to the nut by said apparatus.

J. WILLIAM STIRZEL.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 389,402 Moser Sept. 11, 1888 1,020,964 'Caswell Mar. 26, 1912 1,320,730 Bralove Nov. 4, 1919 1,547,162 Bohlman July 28, 1925 1,670,890 Illmer May 22, 1928 1,895,445 Charpiot Jan. 31, 1933 1,992,730 Zinke et al. Feb. 26, 1935 2,179,724 Kuehne Nov. 14, 1939 2,379,878 Bronander July 10, 1945 2,550,542 Factly Apr. 24, 1951 FOREIGN PATENTS Number Country Date 618,101 France Dec. 1, 1926 

